Following 40 years of declining fertility, echoes of Australia's post-war baby boom are barely discernible in 2002.

Changes in the size and composition of the population, the rate of change, and the way in which change comes about, are to some extent a product of the prevailing economic, political and social conditions, and societal values of the time. In turn, significant population events can have far reaching effects on social and economic conditions and on people's wellbeing and attitudes. Australia's post-war baby boom is such an event. Infant and child health, education, housing and employment are some of the areas of social policy and service provision that have been most affected as the large cohorts of the initial boom (1946-1965), and its first echo in the early 1970s, have progressed through the life cycle.

A cohort analysis of fertility in successive generations of women was undertaken recently by the ABS to find out whether a second echo was likely to occur.(SEE ENDNOTE 1) This article provides a summary of that analysis and discusses some of the economic and social factors contributing to the baby boom and subsequent trends in births and fertility in Australia.

AUSTRALIA'S POST-WAR BABY BOOM

The period from the end of World War II to the mid-1960s has come to be known as the baby boom in Australia and in several other countries including New Zealand, Canada and the United States of America. These were all relatively advanced countries with rapidly expanding economies, rising living standards and serious labour shortages. After the war, these countries welcomed high levels of immigration, and a rapidly growing population was seen as essential to continued economic progress.(SEE ENDNOTE 2) In Australia, a larger population was seen as a defence against possible and perceived threats of invasion.(SEE ENDNOTE 3)

NUMBER OF REGISTERED BIRTHS

BABY BOOM

Baby boom refers to the large and sustained increase in the number of babies born between the end of World War II and the mid-1960s. In Australia, the terms baby boom generation and baby boomers generally relate to all Australian residents born in the years 1946 to 1965, including those who migrated to Australia from countries which did not experience a baby boom. The baby boom echo relates to the children of the baby boom generation. GENERATIONAL EFFECT

The number of births in any given period is a product of two demographic factors - the number of women of reproductive age in the population, and the fertility rates prevalent at the time. In turn, the number of babies born in that period will largely determine the number of women of reproductive age in the next generation which, together with prevailing fertility rates, will determine the number of children born into the following generation, and so on. COHORT ANALYSIS

An analysis of the generational effect set in motion by Australia's post-war baby boom was conducted by the ABS in 2003.(SEE ENDNOTE 1) While a generation is difficult to quantify, such an effect may be studied using the birth cohort as a unit of analysis. A birth cohort is simply ‘a group of people born in the same period’.(SEE ENDNOTE 4) The ABS study uses two single year birth cohorts - 1947 to represent the baby boom generation, and 1971 to represent the first echo generation (i.e. the children of the baby boomers).FERTILITY

Age-specific fertilityrates are the number of live births to mothers at each age per 1,000 of the female population of the same age.

The total fertility rate for any given year is the sum of age-specific fertility rates for that year. It represents the number of children a woman would give birth to during her lifetime if she experienced the current age-specific fertility rates at each age of her reproductive life.

TOTAL FERTILITY RATE - 1932-2002

The first peak of Australia's baby boom occurred in 1947 with 182,400 babies born to couples resuming family lives disrupted by the war. Men left the armed forces and returned to civilian employment. Women relinquished wartime occupations in agriculture and industry and returned to more traditional roles as wives, mothers and homemakers. The two years immediately after the war were characterised by high marriage rates and increasing fertility. Having reached a low of 2.1 during the Great Depression, the total fertility rate peaked at 3.1 in 1947.

Following a brief decline, the number of births increased steadily throughout the 1950s and peaked again in 1961 when 240,000 babies were born. The total fertility rate also peaked in 1961 at 3.5, then fell sharply during the early 1960s, as social and economic changes led to a wider acceptance and use of oral contraceptives (see Australian Social Trends 2002,Fertility futures, pp.12-16).

AGE OF THE 1947 AND 1971 BIRTH COHORTS AND MODAL AGE OF MOTHERS - 1966-2002

The number of births in any given period is the outcome of two demographic factors - the number of women of reproductive age in the population, and the fertility rates prevalent at the time. In all, over four million babies were born in Australia during the baby boom years. As discussed above, this was a period of relatively high fertility. In addition, large scale post-war immigration, mainly of young families and adults in their twenties and thirties, added substantially to the number of women of reproductive age in the Australian population and, subsequently, to the number of babies born. The relatively high ratio of males to females in the immigrant population (e.g. 133:100 in 1954) also increased the opportunities for women already in Australia to marry and have children. The proportion of births in which one or both parents were born overseas increased from 14% in 1947 to 25% in 1961, and 31% in 1965.(SEE ENDNOTE 5)

...THE FIRST ECHO

By the mid-1960s, the total fertility rate had again fallen to below three. Even so, the number of births began to rise again as the first of the baby boomers started families of their own. In 1971, Australia's largest ever cohort was born - 276,400 births. This occurred as the cohort of women born in 1947 reached the peak of their reproductive years. In the years 1970 to 1973 inclusive, the modal (most common) age of mothers giving birth - 23, 24, 25 and 26 years respectively, coincided with the age of the 1947 cohort. The size of this cohort had also been increased by immigration.

While the baby boom lasted for 20 years, the first echo was quickly curtailed as the total fertility rate fell sharply again, from just under 3 in 1971 to 1.9 in 1980. Like the baby boom, the first echo began during a period of strong economic growth and relatively high levels of immigration. While young women in the late 1960s and early 1970s were better educated and more likely to pursue a career than their mothers' generation, the traditional model of family life still prevailed.

However, the 1970s brought many changes in attitudes to women's status and roles within the family, education, labour market, politics and society. The precepts of feminism and individualism exerted a profound influence on all aspects of Australian life. Oral contraceptives became cheaper and more readily available to both married and unmarried women. This allowed women (and their partners) the freedom to delay marriage and to plan the number and spacing of their children to fit in with their education, work and life style aspirations (see Australian Social Trends 1998,Family planning, pp. 29-32).

AGE-SPECIFIC FERTILITY RATES(a) - Selected years

Fertility levels stabilised somewhat during the 1980s then resumed a gradual decline during the 1990s. The generational effect was still discernible during the 1980s and 1990s, with the pattern of births reflecting that of the baby boom. However, the number of births each year was much lower than would have been expected had fertility remained at baby boom levels throughout this period.

...A SECOND ECHO?

If there were to be a second echo of the baby boom, it might have been expected to begin at the turn of the 21st century as the largest ever ‘first echo’ cohort of women reached their peak reproductive years. In the years 1999 to 2001 inclusive, the most common age of mothers giving birth - 28, 29 and 30 years respectively, converged with the age of the 1971 cohort. Following a period of steady decline since 1992, the years 2000 and 2002 saw small increases both in the number of births and in the total fertility rate. While it is too soon to be definitive, this plateau effect may represent a faint second echo, to be followed by a continuation in the downward trend in births and the total fertility rate.

Fertility among women aged 30 years and over increased fairly steadily throughout the 1980s and 1990s (see Australian Social Trends 2001,Older mothers, pp. 55-58) andwomen in the 30-34 years age group currently experience the highest fertility rates. However, these increases did not match the substantial declines in fertility rates among younger women. This has resulted in a much flatter distribution of age-specific fertility rates in 2001 than in 1971, as well as a lower total fertility rate. Consequently, any second echo effect would be less pronounced than the first echo. It might also be prolonged several years if the 1971 cohort of women maintain current fertility levels into their mid to late thirties.

AGE STRUCTURE OF THE POPULATION - JUNE 2003

The fertility patterns described above reflect both the continuing trends of partnering and child bearing at older ages, particularly the delaying of first births, and the growing proportion of women who remain childless. Delaying child bearing reduces the time available for women to have children, thus limiting the likelihood of larger families. It also increases the chances of remaining childless for women who wish to have children but delay to a point where they are no longer able to. On the other hand, more women and couples may be choosing to remain childless.

Childlessness was at its lowest level for the 20th century (9%) among women born between 1930 and 1946. The level of lifetime childlessness began to increase among women born after 1946. Of all women aged 45-49 years at the time of the 1996 census, 11% had never had a child. In 2000, it was estimated that one in four women (who had not yet reached the end of their reproductive lives) would remain childless for life (see Australian Social Trends 2002,Trends in childlessness, pp. 37-40).

CONTINUING EFFECTS OF THE BABY BOOM

Declining fertility has dramatically slowed the rapid population growth initiated by the post-war baby boom. However, the large cohorts born during the original boom and first echo, clearly visible in the current population structure, will continue to influence social and economic policy in Australia well into the 21st century. For example, baby boomers who are currently in their prime working years will soon begin to move out of the work force and into retirement. Between 2011 and 2031, baby boomers will make a significant contribution to the numbers of people aged 65 years and over. During this period, the population aged 65 years and over is projected to grow from 3.2 to 5.7 million. By 2031, all surviving baby boomers will be 65-84 years of age. In the following 20 years, the population aged 85 years and over is projected to almost double, reaching 1.6 million in 2051. (SEE ENDNOTE 6) This has major implications for future policy and planning, particularly in the areas of superannuation and income support, and provision of health and aged care services (see Australian Social Trends 2004,Scenarios for Australia's ageing population, pp. 16-21).